Good argument for designing disc rotors that can't chop off fingers for use in road racing (if ever UCI approved). Just lighten the solid disk with a number of slots or drillium rather than having spokes. There may be interest from the general public too. I'm not that comfortable with having a potential "finger guillotine" on my front wheel. Maybe a better idea is disc guards. This should fix both the problems of rotor burn and losing fingers. But I'm probably being too practical now.

singlespeedscott wrote:Disc brakes will be there because it will be driven by bicycle manufacturers. the manufacturers will lean on the UCI because consumers will want or will be told that they need disc brakes.

But will professional bike riders want them ?

In professional bike races after a wheel change you see the bike riders grabbing onto the team car to get their brakes adjusted by the mechanic.Often this seems like a way to help the rider get back up to speed and catch up with the rest of the group.If there isn't a problem with the disc brake caliper I doubt that a mechanic will pretend to fix it while the bike is moving.If there actually was a problem with the disc brake caliper I doubt that a mechanic will try to fix it while the bike is moving.

Would you try to adjust a disc brake caliper while the bike was travelling at 60 kph ?

There's plenty of nasty photos around of severed fingers from disc brake rotors.

99% of the time that is to aid in getting back up to the cars...they can just adjust the seat post, rear derailleur, lube the chain or cleats... or a gazillion other things .

Would you try to adjust a disc brake caliper while the bike was travelling at 60 kph ?

.....

I've seen Stuey O'G adjust his handlebars riding at 40 km/hr + without hanging on to anything ..

And plenty of other dumb things too whilst guys are riding along and holding on. Also remember a rider in Langkawi (or similar level tour) getting run over by the team car when the holding on bit went a bit wrong.

Anyway, back to the disc discussion.

UCI more than likely wont approve it unless there is a concerted push from MOST of the teams. And since all three manufacturers have a system by the end of the year .....

You are a very knowledgeable bloke, but on this occasion you are mistaken:

(1) most allotropes of carbon are soft & structurally unsuited to the application - pencil anyone ? Sure diamond is the exception, but I think there would be a lot of comments if the discs were diamond.

The brakes currently used by Formula One competitors are similar but different. F1 rotors are instead a carbon-carbon design using carbon-fibers bound together in a carbon matrix without the silicon material found in CCM brakes.

I don't know for sure but just guessing based on what I've heard, sounds like the F1 rotors are reinforced carbon-carbon, like the leading edge panels of the space shuttle as an example. Carbon fibres in a 3D matrix of solid carbon (made by pyrolysis of something like phenolic resin).

MattyK wrote:Yeah, I tried to find a web reference to the construction method, I remember hearing about it years ago, but no luck. They bake them in an oven at about a bazillion degrees for about a month.

Here's a great video on how carbon ceramic brake rotors are made:http://www.youtube.com/watch?v=CAsafGWlSzI1800F for a couple days to make the carbon fibre rotors, the 3000F to melt the silicon (or whatever is being used) and deposit it on the surface of the rotor. I'd imagine a very similar process is used to make those new SiCCC rotors you can get for bikes now.

And yeah, as other people have mentioned, it's just the very thin top surface layer of the brakes that does the actually braking. The second you wear through this and hit the regular carbon fibre below, the rotors are shot. Here's a picture of a failed carbon ceramic rotor (NASCAR) I got from another forum where they're talking about the same thing:

Nice thing about those nifty SiCCC rotors for bikes is that I'd imagine they'll basically last forever, since they'll never see temps anywhere near failure temps.

Well, I took an early adopter one for the team with the Kettle SiCCC-SFL Rotor. It is light, and it looks nice.

It is quiet, has good modulation, and seems to handle heat quite well. It is very civilized. The only problem is that with my Avid BB7 and organic pads it has neither grab nor power. The Highway 9 descent is never above 7%, and it wouldn't bring us to a stop without assistance from the front rim caliper (it wasn't as strong as my ee brake caliper on a carbon rim). I reckon it has only 50% of the power of the Shimano ICE.

For tandems, it might only be useful as a weight weenie measure as one rotor for tandems on gentle terrain wherein two disc brakes are overkill. It might be okay as an ultralight drag brake, as it does handles heat well, and does slow you down. But it is not a brake as in something to brings you to an abrupt halt.

Switching over to the Shimano ICE was soooo nice. Real braking power that dissipates heat. The ICE's power is great on keeping the stoker from wigging out on descents. An occasional twinge on the brake demonstrates to the stoker that things are under powerful control, she is not accelerating headlong to destruction. 89 more grams than the Kettle, but it allowed us to go so much faster with confidence.

I'll keep my Kettle, as Kettle is introducing SiCCC pads that apparently have better grab. I'll wait until I can get the Shimano pads for the TRP Spyre instead of Avid BB7. I'll give it another try then, but on rolling terrain and not a big descent. I figure that I can use the Kettle as part of a weight weenie set up for Low Key Hill Climbs (and for a scale pic on the What does your tandem weigh? thread).

If the SiCCC pads help part of the way, maybe the power-endowed TRP Hy/Rd could take it the rest of the way to being nearly okay.

And here I was thinking that carbon discs were going to be all things to everyone.

so I guess you still think that BB7 are all things for all people too? I had no trouble stopping on a dime with a carbon rotor with XTR calipers and resin pads. Took twenty minutes to burn in the rotor. Next day I was bombing down Mt Nebo with full braking power, the next weekend I was bombing down Mt Buller (Delatite Run anyone??) and had no trouble stopping at all. I only sent my rotor back becuase its warped, not because they didn't work. As soon as the rotors come back they are going straight on both my mountain bike and road bike.

If you read more than that article you will realise that others have had a similar lack of power with them though, and they have changed their finishing process to add more grab.

Crittski wrote:so I guess you still think that BB7 are all things for all people too? I had no trouble stopping on a dime with a carbon rotor with XTR calipers and resin pads. Took twenty minutes to burn in the rotor. Next day I was bombing down Mt Nebo with full braking power, the next weekend I was bombing down Mt Buller (Delatite Run anyone??) and had no trouble stopping at all. I only sent my rotor back becuase its warped, not because they didn't work. As soon as the rotors come back they are going straight on both my mountain bike and road bike.

If you read more than that article you will realise that others have had a similar lack of power with them though, and they have changed their finishing process to add more grab.

No, I'm a Bengal bloke, Avids have plastic bits that melt. I'd happily concede that hydraulic brakes have distinct advantages particularly when there is a long cable run such as on a tandem.

These were promised to be very light (to negate the weight weenie argument against disc brakes on road bikes)They also promised to have very high heat capacity (to negate the argument that road bikes descending mountains create more heat than mountain bikes)They're carbon so they have bling factor,and they were supposed to work as well at low speeds as any others.

The only downside was supposed to be the price.

The review I posted said they don't work as well as hoped, but that maybe the new pads would be better.You said that they used to be like that but they've been improved. You also said that they warp.

I say that they won't be considered for any of my bikes until they have a better service history, because they are not the perfect solution yet.

Crittski wrote:so I guess you still think that BB7 are all things for all people too? I had no trouble stopping on a dime with a carbon rotor with XTR calipers and resin pads. Took twenty minutes to burn in the rotor. Next day I was bombing down Mt Nebo with full braking power, the next weekend I was bombing down Mt Buller (Delatite Run anyone??) and had no trouble stopping at all. I only sent my rotor back becuase its warped, not because they didn't work. As soon as the rotors come back they are going straight on both my mountain bike and road bike.

If you read more than that article you will realise that others have had a similar lack of power with them though, and they have changed their finishing process to add more grab.

I've got a BB7 and in some ways it's complete crap. Adjusting it to work nicely is virtually impossible. I have trouble recommending the BB7.

cooperplace wrote:I've got a BB7 and in some ways it's complete crap. Adjusting it to work nicely is virtually impossible. I have trouble recommending the BB7.

They can be a PITA to get right, but braking is still pretty good with them.

Ahhhh, to have discs and mudguards

Last nights ride up Mt Osmond was great. Balmy conditions going up, and then rain going down and the rest of the way home. A good example of why disc brakes are a good thing on a road bike (the descent of Mt Osmond is short but steep with lots of corners), and proper mudguards to stop getting covered in crap !!

ironhanglider wrote:No, I'm a Bengal bloke, Avids have plastic bits that melt. I'd happily concede that hydraulic brakes have distinct advantages particularly when there is a long cable run such as on a tandem.

You may wish to note that most brake manufacturers specifically recommend NOT fitting hydros to tandems, the reason being that the substantially higher load placed on the system poses a very real risk of overheating the fluid, resulting in vapour lock (fluid boiling and creating gas bubbles inside the system, for those unfamiliar with the term) and complete brake failure. Shimano's Ice Tech system may address the concern to an extent, but the fact that mineral oil has an inherently lower boiling point than DOT fluid means it's still not certain that Ice Tech would make enough of a difference.

And the hydros on my commuter and MTB are even easier. No cable stretch or fraying. No turning dials or barrel adjusters as the pads wear. I've been waiting for when they need bleeding, but it's never happened.

I even made it back to the car without rubbing despite a massive wheel buckle courtesy of a big hit on my CX during a dirt descent in the Strzeleckis.

clackers wrote:And the hydros on my commuter and MTB are even easier. No cable stretch or fraying. No turning dials or barrel adjusters as the pads wear. I've been waiting for when they need bleeding, but it's never happened.

Same, with the hydros on my MTB...

...EXCEPT...

...for the one time they did need bleeding, and I was out in the bush with a disabled bike and absolutely no way to fix it.

That was a frustrating ride. Drove 20km, rode slowly about 4km waiting for the front brake to come good, admitted it wasn't going to, rode slowly 4km back to the car, drove 20km home to my previously unused bleed kit.

Granted, they've been absolutely flawless since then. They just had a bubble in them from the factory, which is apparently not uncommon with Elixirs. But it highlighted to me just how helpless you are if you have issues in the field with hydraulic brakes. They're great when they work, they're extremely reliable so it's unlikely that you'll ever have a problem... but if you do...

I even made it back to the car without rubbing despite a massive wheel buckle courtesy of a big hit on my CX during a dirt descent in the Strzeleckis.

Same. Although it gets a bit interesting riding technical cross-slopes on a wheel that steps out by an inch every rev

Why would I ever go back to rim brakes?

...and that's why, when I bit the bullet and decided to built a custom road bike frame, it was never going to have rim brakes.

barefoot wrote:...for the one time they did need bleeding, and I was out in the bush with a disabled bike and absolutely no way to fix it.

That was a frustrating ride. Drove 20km, rode slowly about 4km waiting for the front brake to come good, admitted it wasn't going to, rode slowly 4km back to the car, drove 20km home to my previously unused bleed kit.

tim

Why didn't you just undo the caliper and wrap it around the handlebars? You still would of had the other brake.

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